How to configure keepalive when I use asp.net core 3.0 grpc?

I want to do service push by grpc in asp.net core 3.0, so I want to configure keepalive like new ChannelOption("grpc.keepalive_permit_without_calls", 1), but I found I can use channel option when I use Grpc.Net.Client.GrpcChannel. It is there anything I can do to keepalive my request steam? thanks